


If I promise to do better (will you maybe change your mind)

by Captain_of_the_sass



Category: Captain America (Movies), The Avengers (Marvel Movies)
Genre: Age Regression/De-Aging, Enemies to Friends to Lovers, M/M, Miscommunication, Misunderstandings, Not Avengers: Age of Ultron (Movie) Compliant, Tony is secretly good with kids
Language: English
Status: In-Progress
Published: 2015-10-16
Updated: 2015-10-16
Packaged: 2018-04-26 14:32:51
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 1,897
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5008423
Author URL: https://archiveofourown.org/users/Captain_of_the_sass/pseuds/Captain_of_the_sass
Summary: <blockquote class="userstuff">
              <p>Tony was a superhero. He'd built himself a heart out of scraps in a cave, he could totally handle five kids and a super-soldier who hated his guts. Or at least that's what he kept telling himself.</p><p>AKA the one where the rest of the team is de-aged and Bucky and Tony are saddled with babysitting duty.</p>
            </blockquote>





	If I promise to do better (will you maybe change your mind)

**Author's Note:**

> So this is my first fic I've written in years, be gentle with me okay? I don't have a beta so if you find any errors please feel free to let me know, and find me on tumblr if you'd like: my URL is tonybuckys

Bucky hates Tony. It was one of those universal facts of life that Tony knew with absolute certainty; the Earth rotates around the sun, fire is hot, and Bucky Barnes hates Tony Stark. It was nothing new, honestly. He had long grown used to people hating him, it was just another one of the joys of being Tony. His ability to ignore other people’s shitty opinions of him was a point of pride, almost. Yet somehow Barnes’ frosty reception was seriously pissing him off. Probably because Tony had actually _tried_ with him.

For weeks following the Winter Soldier’s recovery Steve just wouldn’t shut up about the guy. Countless stories about a kid with a mischievous grin, a smooth talking schoolboy, and a man that always had Steve’s back. Tony was torn between loving Barnes and wanting to choke him.

“He’s getting better everyday,” Steve had said, “You’re gonna love ‘im, Tony.” Of course there were bad days too. Days where Steve returned from whatever place they’d holed Barnes up in with haunted eyes. On those days Steve simply took his usual seat in Tony’s workshop, listening in eerie silence while Tony babbled continuously, just trying to wipe the empty look off his friend’s face. He worried about Steve and (though he really hated to admit it to himself) he worried about Bucky too (Barnes, Tony. _Barnes_ ).

Who could blame him? Steve was one hell of a storyteller.

Which was why, when the guy finally brought Barnes to the tower for the first time, Tony was on his best behavior. He put on the only pair of jeans he owned without any holes in them, smiled his best smile, and shook hands just like he’d done a million times before. And as soon as he heard Tony’s name Barnes’ face closed off completely, lips tight.

“Nice to meet you,” he’d said, but it kinda looked like the guy wanted to punch Tony in the face. Still, Tony made an attempt to start a civil conversation and Bucky shot it down immediately, completely tuning Tony out and turning his attention to Steve.

“Sorry, could you show me where the bathroom is?” Barnes demanded. Steve glanced between him and Tony, his brows furrowed as if he were trying to solve a puzzle.

“Sure, of course.” Steve assured, giving Tony an apologetic glance as he led Barnes away, leaving the genius feeling strangely hollow inside. He wouldn’t give up, though. Tony tried starting casual talks, sitting next to the guy at movie nights, hell- he even tried giving the guy a gift basket full of all the great junk foods Barnes had probably never gotten a chance to try. He found the basket sitting outside his bedroom door unopened the next day.

 _Fuck Barnes_ , he decided. The guy clearly wanted nothing to do with him so why bother? Normally Tony would just be a dick right back to the guy, but this was Bucky. This was Steve’s best friend and (though Tony would never admit it) he didn’t want to disappoint Steve by picking a fight with his brainwashed BFF. So he tried actively trying to avoid the guy instead, pointedly ignoring the crestfallen look on Steve’s face whenever Tony casually departed the room as soon as Barnes made an appearance. The others started to notice it, too. Natasha simply raised one perfect brow at Tony’s excuses, watching him flee the room like he was a science project she wanted to pick apart while Clint started whispering countdowns, trying to see how long Tony could hold out before inevitably making his escape.

Things came to a head the night Tony got back from some awful gala Pepper had talked him into attending. He’d spent the whole night drinking and schmoozing, smiling at people who didn’t actually give a damn about the Stark Relief project. They were here to be seen, to look good in front of a whole ballroom full of people who also didn’t really give a damn about anything other than their reputations and free cocktails. Some of them were genuine. Some of them were honest good people, but not enough to keep Tony from feeling exhausted by the end of it all. He dragged himself back to the tower sometime around four in the morning, worn out and more than a little tipsy. So of course, when the elevator doors opened to reveal Barnes looming _right the fuck_ there, eyes narrowed and barely visible in the near-darkness, Tony went off.

“Seriously, can you not give me one night of peace?” he hollered, “I get it already; you think I’m an asshole. Well that’s nothing new, Sweetie, so if you think you’re gonna get to me with the whole _glaring daggers_ thing you’re doing you’re wrong.” Tony practically spat the last word before marching by him, making a beeline for the bar. He flicked on the single light that hung above the liquor shelves, the clattering of his glass against the counter sounding deafening in the silence as Tony got himself a drink. He took a greedy sip, knuckles white with how hard he gripped the glass, then he abruptly brought it down to rest on the bar, dropping his head and pressing his forehead into the cool surface, eyes closed. Quiet. It was so, so quiet. He figured that Barnes had probably stormed off to brood somewhere so when a firm voice spoke from the shadows Tony nearly jumped out of his skin, head snapping up.

“You _are_ an asshole.” Barnes said, but he didn’t sound smug about it. He just sounded like Tony had simply confirmed everything Barnes had already knew. The ex-assassin's jaw clenched tightly when he muttered, “I don’t get what Steve sees in you.”

And _what_?

“What the fuck?” Tony blurted, but Barnes had already turned on his heel and stalked away. After that night Barnes seemed to have no qualms about egging Tony on. There were quick jabs that might have been considered jokes had they been friends, but between them they were as sharp as knifes. Bruce started to give the two a wide berth whenever the were in the room together, having to step in on more than one occasion to keep the two from biting each other’s heads off. With Steve in the room Barnes maintained a civil appearance, but as soon as Cap turned his back the guy was unbelievable. Tony refused to take Barnes’ shit lying down, though. He gave as good as he got; years of practice had taught him to hit right where it hurt. Jibes about Barnes following Steve around like a dog, how he seemed incapable of thinking for himself, how he just had to be right about everything no matter the consequences. Their fights were swift and brutal, just dripping with venom. Every time they were within ten feet of each other they were either fighting or getting ready to. Barnes was always pissy about how Tony should show Steve more respect, how he should actually listen when people are speaking to him, and how he should stop spending all his time hiding in his lab and sulking. Tony’d never met a more hypocritical asshole. There were only two settings on Barnes: loud and obnoxious or dark and brooding, there was no in between.

Bucky hated Tony, and Tony hated him right back.

So, naturally, when Agent Coulson tried to dump a wailing miniature Steve Rogers into Tony’s arms he immediately backed away as if the kid were a live bomb.

“Oh no. Hell no, in big bold capital letters,” He blurted, “I am not playing house with Barnes and the superhero Brady bunch.” And seriously? How bad was his luck that the rest of his team had managed to go and get themselves turned into drooling toddlers and left him stuck with fucking Bucky Barnes of all people? They couldn’t get along even on their best days, let alone with five unruly kids between them.

“For once I agree with Stark,” Barnes admitted, “We’re the last people who should be trusted to be anywhere near babies; especially not, well-” he gestured to Steve, sniffling in Coulson’s arms, and the rest of the pack of kids at the agent’s feet.

“’M not a baby,” Tiny Steve growled through his tears, apparently deciding to join the conversation, “I’m almost four.”

 _You’re about ninety years off, give or take_ Tony thought to himself. The little boy scrubbed away the tears on his cheeks with chubby little fists while Coulson tilted his head to look at him. 

“Four?” the man prodded, smiling at Tiny Steve like he’d hung the stars in the sky, “Are you sure about that? You’re awfully tall to be four.” A pretty damn big understatement. It’d taken the SHIELD medical team less than five minutes to determine that this shrunken Steve still had the super serum running through his veins. The sight of the full rosy-cheeked little boy in front of Tony clashed with the image of the sickly child in Steve’s stories and Tony was having trouble reconciling the two. Luckily Tiny Steve didn’t seem to have noticed the growth spurt, or if he had the kid hadn’t said anything. Tony’s thoughts were interrupted by a rough yank at the hem of his shirt. He looked down to find one of the minivengers glaring up at him. Short sandy blonde hair. Clint, maybe?

“I need to pee.” The kid announced. Definitely Clint. Tony swung a wide-eyed gaze at Coulson, trying to appeal to any shred of humanity the guy had left.

“ _Agent_.”

“They can’t stay here anymore, Tony.”

“It’s only been two days!”  

“Yes, and this is a government agency not a daycare,” Coulson reminded him with a chagrined smile, “And the med staff told me to get them out of here after Thor somehow managed to destroy the medbay doors, four computers, and a coffee machine.”

“And you want me to bring _that_ into the tower?” Tony practically screeched, “Barnes, back me up for once in your life. This has got to be the worst idea-“ but when Tony finally looked over he found Bucky completely oblivious to the conversation. He was staring down at Tiny Natasha, lips slightly parted as he carefully held his flesh and blood hand out, letting her drop something into the center of his palm. Natasha smiled and fired off something in Russian too quiet for Tony to catch, turning her head to the side to gesture to the ponytail holding her hair back. Whatever she said made a tentative smile break over Barnes’ face, washing away the exhaustion that had lingered there ever since Steve had become pint-sized (or long before that, if Tony was being honest). Barnes murmured something back to Natasha and, though his Russian was pretty rusty lately, Tony thought he might have caught a “thank you” in there somewhere. Slowly Barnes lifted his hands to his hair and starting combing it back, and Tony realized as the soldier fumbled the long strands into a poor excuse for a bun that Natasha had given him one of the hair ties that circled her wrist. Bruce warily approached the two, staring up at Barnes with big curious eyes.

Coulson cracked a triumphant grin and Tony pointed a finger at him in warning.

“I’m serious, there will be no children in my tower.”


End file.
